Balancing stroker kit ???

You might as well go for the 4" stroke as there is no extra cost and cubes matter. The pistons should be selected based on your heads and the desired compression ratio. The kit might be rated for 600hp but my guess is that you will be in the 400 hp range with stock heads. I would get a better cam recommendation from a reputable cam company based on your final combination (heads/compression/hp goal/use). 212 [email protected] is pretty mild. There is no point in increasing stroke if you can't fill the cylinders. Based on my experiences with aftermarket parts, I would check all fits/clearances and be prepared for some machine shop work for making things right. On a budget, I would perhaps just go with a stock bottom end rebuild. The other option is to spend the $$$ on the bottom end as you can always upgrade cam, heads, intake later. Good luck with the project!